The present invention relates, in general, to a timer and circuit board assembly, and more particularly, to an improved timer and circuit board assembly for use in a regenerative desiccant air dryer.
Prior to the present invention, the electronic components of a timer and circuit board assembly for use in a regenerative desiccant air dryer are mounted on the circuit board, which is inserted into a housing in the air dryer. To minimize exposure to undesirable environmental elements such as water or dirt, which can potentially cause failure, a tight fitting gasket is required between the housing and the housing cover. The seal of this gasket is critical to the proper function and consistent operation of the timer and circuit board assembly. If the seal fails in service, water and dirt can infiltrate the circuit board. This exposure makes the electronic components on the board extremely vulnerable to failure by creating a bridge between the exposed electrical circuits.
An example of this type of timer and circuit board assembly is taught in the Graham-White 975 Series Twin Tower Air Filter Dryer. The teachings of this reference are incorporated herein by reference thereto.
In a first aspect, the present invention provides a potted timer and circuit board assembly for use in a regenerative desiccant air dryer. The potted timer and circuit board assembly comprises a support member of a predetermined size and shape having a first surface and a second surface. A conductive pattern of a predetermined material and thickness is disposed on at least one of the first surface and the second surface of the support member. A predetermined quantity and arrangement of electronic components of a predetermined voltage is disposed on at least one of the first surface and the second surface of the support member for providing a timed electronic signal to a solenoid valve that pneumatically operates an air dryer. A non-conductive material of a predetermined composition encases the electronic components on the support member for insulating the electronic components from environmental elements. At least one exposed member on a side of the support member engages with at least one receptacle on an air dryer for creating an electrical current in the potted timer and circuit board assembly. An alignment means is disposed on at least one of the opposing sides of the support member for engagement with at least one slot in an air dryer for aligning and holding the potted timer and circuit board assembly in a predetermined position in an air dryer.
In still a further aspect, the present invention provides a potted timer and circuit board assembly in combination with a regenerative desiccant air dryer having a dehydrating dryer, a regenerating dryer, outlet check valves, inlet check valves, solenoid valves, a pre-coalescer, purge valves, and a drain valve. The improvement comprises a support member of a predetermined size and shape having a first surface and a second surface. A conductive pattern of a predetermined material and thickness is disposed on at least one of the first surface and the second surface of the support member. A predetermined quantity and arrangement of electronic components of a predetermined voltage is disposed on at least one of the first surface and the second surface of the support member for providing a timed electronic signal to a solenoid valve that pneumatically operates an air dryer. A non-conductive material of a predetermined composition encases the electronic components on the support member for insulating the electronic components from environmental elements. At least one exposed member on a side of the support member engages with at least one receptacle on an air dryer for creating an electrical current in the potted timer and circuit board assembly. An alignment means is disposed on at least one of the opposing sides of the support member for engagement with at least one slot in an air dryer for aligning and holding the potted timer and circuit board assembly in a predetermined position in an air dryer.
In addition to the various objects of the invention that have been described above, various other objects and advantages of the invention will become more readily apparent to those persons skilled in the relevant art from the following more detailed description of the invention, particularly, when such description is taken in conjunction with the attached drawing figures and the appended claims.